Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 984 insertions, 0 deletions

diff --git a/storage/innobase/trx/trx0roll.cc b/storage/innobase/trx/trx0roll.cc
new file mode 100644
index 00000000..23aa950a
--- /dev/null
+++ b/storage/innobase/trx/trx0roll.cc
@@ -0,0 +1,984 @@
+/*****************************************************************************
+
+Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2016, 2021, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file trx/trx0roll.cc
+Transaction rollback
+
+Created 3/26/1996 Heikki Tuuri
+*******************************************************/
+
+#include "trx0roll.h"
+
+#include <my_service_manager.h>
+#include <mysql/service_wsrep.h>
+
+#include "fsp0fsp.h"
+#include "lock0lock.h"
+#include "mach0data.h"
+#include "pars0pars.h"
+#include "que0que.h"
+#include "row0mysql.h"
+#include "row0undo.h"
+#include "srv0mon.h"
+#include "srv0start.h"
+#include "trx0rec.h"
+#include "trx0rseg.h"
+#include "trx0sys.h"
+#include "trx0trx.h"
+#include "trx0undo.h"
+
+#ifdef UNIV_PFS_THREAD
+mysql_pfs_key_t	trx_rollback_clean_thread_key;
+#endif
+
+/** true if trx_rollback_all_recovered() thread is active */
+bool			trx_rollback_is_active;
+
+/** In crash recovery, the current trx to be rolled back; NULL otherwise */
+const trx_t*		trx_roll_crash_recv_trx;
+
+/** Finish transaction rollback.
+@return	whether the rollback was completed normally
+@retval	false	if the rollback was aborted by shutdown  */
+inline bool trx_t::rollback_finish()
+{
+  mod_tables.clear();
+  if (UNIV_LIKELY(error_state == DB_SUCCESS))
+  {
+    commit();
+    return true;
+  }
+
+  ut_a(error_state == DB_INTERRUPTED);
+  ut_ad(srv_shutdown_state != SRV_SHUTDOWN_NONE);
+  ut_a(!srv_undo_sources);
+  ut_ad(srv_fast_shutdown);
+  ut_d(in_rollback= false);
+  if (trx_undo_t *&undo= rsegs.m_redo.undo)
+  {
+    UT_LIST_REMOVE(rsegs.m_redo.rseg->undo_list, undo);
+    ut_free(undo);
+    undo= nullptr;
+  }
+  if (trx_undo_t *&undo= rsegs.m_noredo.undo)
+  {
+    UT_LIST_REMOVE(rsegs.m_noredo.rseg->undo_list, undo);
+    ut_free(undo);
+    undo= nullptr;
+  }
+  commit_low();
+  lock.que_state= TRX_QUE_RUNNING;
+  return false;
+}
+
+/** Roll back an active transaction. */
+inline void trx_t::rollback_low(trx_savept_t *savept)
+{
+  mem_heap_t *heap= mem_heap_create(512);
+  roll_node_t *roll_node= roll_node_create(heap);
+  roll_node->savept= savept;
+
+  ut_ad(!in_rollback);
+#ifdef UNIV_DEBUG
+  {
+    const auto s= state;
+    ut_ad(s == TRX_STATE_ACTIVE ||
+          s == TRX_STATE_PREPARED ||
+          s == TRX_STATE_PREPARED_RECOVERED);
+    if (savept)
+    {
+      ut_ad(s == TRX_STATE_ACTIVE);
+      ut_ad(mysql_thd);
+      ut_ad(!is_recovered);
+    }
+  }
+#endif
+
+  error_state = DB_SUCCESS;
+
+  if (has_logged())
+  {
+    ut_ad(rsegs.m_redo.rseg || rsegs.m_noredo.rseg);
+    que_thr_t *thr= pars_complete_graph_for_exec(roll_node, this, heap,
+                                                 nullptr);
+    ut_a(thr == que_fork_start_command(static_cast<que_fork_t*>
+                                       (que_node_get_parent(thr))));
+    que_run_threads(thr);
+    que_run_threads(roll_node->undo_thr);
+
+    /* Free the memory reserved by the undo graph. */
+    que_graph_free(static_cast<que_t*>(roll_node->undo_thr->common.parent));
+  }
+
+  if (!savept)
+  {
+    rollback_finish();
+    MONITOR_INC(MONITOR_TRX_ROLLBACK);
+  }
+  else
+  {
+    ut_a(error_state == DB_SUCCESS);
+    const undo_no_t limit= savept->least_undo_no;
+    for (trx_mod_tables_t::iterator i= mod_tables.begin();
+	 i != mod_tables.end(); )
+    {
+      trx_mod_tables_t::iterator j= i++;
+      ut_ad(j->second.valid());
+      if (j->second.rollback(limit))
+        mod_tables.erase(j);
+    }
+    lock.que_state= TRX_QUE_RUNNING;
+    MONITOR_INC(MONITOR_TRX_ROLLBACK_SAVEPOINT);
+  }
+
+  mem_heap_free(heap);
+
+  MONITOR_DEC(MONITOR_TRX_ACTIVE);
+}
+
+/** Initiate rollback.
+@param savept     savepoint
+@return error code or DB_SUCCESS */
+dberr_t trx_t::rollback(trx_savept_t *savept)
+{
+  ut_ad(!trx_mutex_own(this));
+  if (state == TRX_STATE_NOT_STARTED)
+  {
+    error_state= DB_SUCCESS;
+    return DB_SUCCESS;
+  }
+  ut_ad(state == TRX_STATE_ACTIVE);
+#ifdef WITH_WSREP
+  if (!savept && is_wsrep() && wsrep_thd_is_SR(mysql_thd))
+    wsrep_handle_SR_rollback(nullptr, mysql_thd);
+#endif /* WITH_WSREP */
+  rollback_low(savept);
+  return error_state;
+}
+
+/*******************************************************************//**
+Rollback a transaction used in MySQL.
+@return error code or DB_SUCCESS */
+static
+dberr_t
+trx_rollback_for_mysql_low(
+/*=======================*/
+	trx_t*	trx)	/*!< in/out: transaction */
+{
+	trx->op_info = "rollback";
+
+	/* If we are doing the XA recovery of prepared transactions,
+	then the transaction object does not have an InnoDB session
+	object, and we set a dummy session that we use for all MySQL
+	transactions. */
+
+	trx->rollback_low();
+
+	trx->op_info = "";
+
+	return(trx->error_state);
+}
+
+/** Rollback a transaction used in MySQL
+@param[in, out]	trx	transaction
+@return error code or DB_SUCCESS */
+dberr_t trx_rollback_for_mysql(trx_t* trx)
+{
+	/* We are reading trx->state without holding trx->mutex
+	here, because the rollback should be invoked for a running
+	active MySQL transaction (or recovered prepared transaction)
+	that is associated with the current thread. */
+
+	switch (trx->state) {
+	case TRX_STATE_NOT_STARTED:
+		trx->will_lock = false;
+		ut_ad(trx->mysql_thd);
+#ifdef WITH_WSREP
+		trx->wsrep= false;
+		trx->lock.was_chosen_as_wsrep_victim= false;
+#endif
+		return(DB_SUCCESS);
+
+	case TRX_STATE_ACTIVE:
+		ut_ad(trx->mysql_thd);
+		ut_ad(!trx->is_recovered);
+		ut_ad(!trx->is_autocommit_non_locking() || trx->read_only);
+		return(trx_rollback_for_mysql_low(trx));
+
+	case TRX_STATE_PREPARED:
+	case TRX_STATE_PREPARED_RECOVERED:
+		ut_ad(!trx->is_autocommit_non_locking());
+		if (trx->rsegs.m_redo.undo) {
+			/* The XA ROLLBACK of a XA PREPARE transaction
+			will consist of multiple mini-transactions.
+
+			As the very first step of XA ROLLBACK, we must
+			change the undo log state back from
+			TRX_UNDO_PREPARED to TRX_UNDO_ACTIVE, in order
+			to ensure that recovery will complete the
+			rollback.
+
+			Failure to perform this step could cause a
+			situation where we would roll back part of
+			a XA PREPARE transaction, the server would be
+			killed, and finally, the transaction would be
+			recovered in XA PREPARE state, with some of
+			the actions already having been rolled back. */
+			ut_ad(trx->rsegs.m_redo.undo->rseg
+			      == trx->rsegs.m_redo.rseg);
+			mtr_t		mtr;
+			mtr.start();
+			mutex_enter(&trx->rsegs.m_redo.rseg->mutex);
+			if (trx_undo_t* undo = trx->rsegs.m_redo.undo) {
+				trx_undo_set_state_at_prepare(trx, undo, true,
+							      &mtr);
+			}
+			mutex_exit(&trx->rsegs.m_redo.rseg->mutex);
+			/* Write the redo log for the XA ROLLBACK
+			state change to the global buffer. It is
+			not necessary to flush the redo log. If
+			a durable log write of a later mini-transaction
+			takes place for whatever reason, then this state
+			change will be durable as well. */
+			mtr.commit();
+			ut_ad(mtr.commit_lsn() > 0);
+		}
+		return(trx_rollback_for_mysql_low(trx));
+
+	case TRX_STATE_COMMITTED_IN_MEMORY:
+		ut_ad(!trx->is_autocommit_non_locking());
+		break;
+	}
+
+	ut_error;
+	return(DB_CORRUPTION);
+}
+
+/*******************************************************************//**
+Rollback the latest SQL statement for MySQL.
+@return error code or DB_SUCCESS */
+dberr_t
+trx_rollback_last_sql_stat_for_mysql(
+/*=================================*/
+	trx_t*	trx)	/*!< in/out: transaction */
+{
+	dberr_t	err;
+
+	/* We are reading trx->state without holding trx->mutex
+	here, because the statement rollback should be invoked for a
+	running active MySQL transaction that is associated with the
+	current thread. */
+	ut_ad(trx->mysql_thd);
+
+	switch (trx->state) {
+	case TRX_STATE_NOT_STARTED:
+		return(DB_SUCCESS);
+
+	case TRX_STATE_ACTIVE:
+		ut_ad(trx->mysql_thd);
+		ut_ad(!trx->is_recovered);
+		ut_ad(!trx->is_autocommit_non_locking() || trx->read_only);
+
+		trx->op_info = "rollback of SQL statement";
+
+		err = trx->rollback(&trx->last_sql_stat_start);
+
+		if (trx->fts_trx != NULL) {
+			fts_savepoint_rollback_last_stmt(trx);
+		}
+
+		/* The following call should not be needed,
+		but we play it safe: */
+		trx_mark_sql_stat_end(trx);
+
+		trx->op_info = "";
+
+		return(err);
+
+	case TRX_STATE_PREPARED:
+	case TRX_STATE_PREPARED_RECOVERED:
+	case TRX_STATE_COMMITTED_IN_MEMORY:
+		/* The statement rollback is only allowed on an ACTIVE
+		transaction, not a PREPARED or COMMITTED one. */
+		break;
+	}
+
+	ut_error;
+	return(DB_CORRUPTION);
+}
+
+/*******************************************************************//**
+Search for a savepoint using name.
+@return savepoint if found else NULL */
+static
+trx_named_savept_t*
+trx_savepoint_find(
+/*===============*/
+	trx_t*		trx,			/*!< in: transaction */
+	const char*	name)			/*!< in: savepoint name */
+{
+	trx_named_savept_t*	savep;
+
+	for (savep = UT_LIST_GET_FIRST(trx->trx_savepoints);
+	     savep != NULL;
+	     savep = UT_LIST_GET_NEXT(trx_savepoints, savep)) {
+		if (!strcmp(savep->name, name)) {
+			return(savep);
+		}
+	}
+
+	return(NULL);
+}
+
+/*******************************************************************//**
+Frees a single savepoint struct. */
+static
+void
+trx_roll_savepoint_free(
+/*=====================*/
+	trx_t*			trx,	/*!< in: transaction handle */
+	trx_named_savept_t*	savep)	/*!< in: savepoint to free */
+{
+	UT_LIST_REMOVE(trx->trx_savepoints, savep);
+
+	ut_free(savep->name);
+	ut_free(savep);
+}
+
+/*******************************************************************//**
+Frees savepoint structs starting from savep. */
+void
+trx_roll_savepoints_free(
+/*=====================*/
+	trx_t*			trx,	/*!< in: transaction handle */
+	trx_named_savept_t*	savep)	/*!< in: free all savepoints starting
+					with this savepoint i*/
+{
+	while (savep != NULL) {
+		trx_named_savept_t*	next_savep;
+
+		next_savep = UT_LIST_GET_NEXT(trx_savepoints, savep);
+
+		trx_roll_savepoint_free(trx, savep);
+
+		savep = next_savep;
+	}
+}
+
+/*******************************************************************//**
+Rolls back a transaction back to a named savepoint. Modifications after the
+savepoint are undone but InnoDB does NOT release the corresponding locks
+which are stored in memory. If a lock is 'implicit', that is, a new inserted
+row holds a lock where the lock information is carried by the trx id stored in
+the row, these locks are naturally released in the rollback. Savepoints which
+were set after this savepoint are deleted.
+@return if no savepoint of the name found then DB_NO_SAVEPOINT,
+otherwise DB_SUCCESS */
+static MY_ATTRIBUTE((nonnull, warn_unused_result))
+dberr_t
+trx_rollback_to_savepoint_for_mysql_low(
+/*====================================*/
+	trx_t*			trx,	/*!< in/out: transaction */
+	trx_named_savept_t*	savep,	/*!< in/out: savepoint */
+	int64_t*		mysql_binlog_cache_pos)
+					/*!< out: the MySQL binlog
+					cache position corresponding
+					to this savepoint; MySQL needs
+					this information to remove the
+					binlog entries of the queries
+					executed after the savepoint */
+{
+	dberr_t	err;
+
+	ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE));
+	ut_ad(trx->mysql_thd);
+
+	/* Free all savepoints strictly later than savep. */
+
+	trx_roll_savepoints_free(
+		trx, UT_LIST_GET_NEXT(trx_savepoints, savep));
+
+	*mysql_binlog_cache_pos = savep->mysql_binlog_cache_pos;
+
+	trx->op_info = "rollback to a savepoint";
+
+	err = trx->rollback(&savep->savept);
+
+	/* Store the current undo_no of the transaction so that
+	we know where to roll back if we have to roll back the
+	next SQL statement: */
+
+	trx_mark_sql_stat_end(trx);
+
+	trx->op_info = "";
+#ifdef WITH_WSREP
+	trx->lock.was_chosen_as_wsrep_victim = false;
+#endif
+	return(err);
+}
+
+/*******************************************************************//**
+Rolls back a transaction back to a named savepoint. Modifications after the
+savepoint are undone but InnoDB does NOT release the corresponding locks
+which are stored in memory. If a lock is 'implicit', that is, a new inserted
+row holds a lock where the lock information is carried by the trx id stored in
+the row, these locks are naturally released in the rollback. Savepoints which
+were set after this savepoint are deleted.
+@return if no savepoint of the name found then DB_NO_SAVEPOINT,
+otherwise DB_SUCCESS */
+dberr_t
+trx_rollback_to_savepoint_for_mysql(
+/*================================*/
+	trx_t*		trx,			/*!< in: transaction handle */
+	const char*	savepoint_name,		/*!< in: savepoint name */
+	int64_t*	mysql_binlog_cache_pos)	/*!< out: the MySQL binlog cache
+						position corresponding to this
+						savepoint; MySQL needs this
+						information to remove the
+						binlog entries of the queries
+						executed after the savepoint */
+{
+	trx_named_savept_t*	savep;
+
+	/* We are reading trx->state without holding trx->mutex
+	here, because the savepoint rollback should be invoked for a
+	running active MySQL transaction that is associated with the
+	current thread. */
+	ut_ad(trx->mysql_thd);
+
+	savep = trx_savepoint_find(trx, savepoint_name);
+
+	if (savep == NULL) {
+		return(DB_NO_SAVEPOINT);
+	}
+
+	switch (trx->state) {
+	case TRX_STATE_NOT_STARTED:
+		ib::error() << "Transaction has a savepoint "
+			<< savep->name
+			<< " though it is not started";
+		return(DB_ERROR);
+
+	case TRX_STATE_ACTIVE:
+
+		return(trx_rollback_to_savepoint_for_mysql_low(
+				trx, savep, mysql_binlog_cache_pos));
+
+	case TRX_STATE_PREPARED:
+	case TRX_STATE_PREPARED_RECOVERED:
+	case TRX_STATE_COMMITTED_IN_MEMORY:
+		/* The savepoint rollback is only allowed on an ACTIVE
+		transaction, not a PREPARED or COMMITTED one. */
+		break;
+	}
+
+	ut_error;
+	return(DB_CORRUPTION);
+}
+
+/*******************************************************************//**
+Creates a named savepoint. If the transaction is not yet started, starts it.
+If there is already a savepoint of the same name, this call erases that old
+savepoint and replaces it with a new. Savepoints are deleted in a transaction
+commit or rollback.
+@return always DB_SUCCESS */
+dberr_t
+trx_savepoint_for_mysql(
+/*====================*/
+	trx_t*		trx,			/*!< in: transaction handle */
+	const char*	savepoint_name,		/*!< in: savepoint name */
+	int64_t		binlog_cache_pos)	/*!< in: MySQL binlog cache
+						position corresponding to this
+						connection at the time of the
+						savepoint */
+{
+	trx_named_savept_t*	savep;
+
+	trx_start_if_not_started_xa(trx, false);
+
+	savep = trx_savepoint_find(trx, savepoint_name);
+
+	if (savep) {
+		/* There is a savepoint with the same name: free that */
+
+		UT_LIST_REMOVE(trx->trx_savepoints, savep);
+
+		ut_free(savep->name);
+		ut_free(savep);
+	}
+
+	/* Create a new savepoint and add it as the last in the list */
+
+	savep = static_cast<trx_named_savept_t*>(
+		ut_malloc_nokey(sizeof(*savep)));
+
+	savep->name = mem_strdup(savepoint_name);
+
+	savep->savept = trx_savept_take(trx);
+
+	savep->mysql_binlog_cache_pos = binlog_cache_pos;
+
+	UT_LIST_ADD_LAST(trx->trx_savepoints, savep);
+
+	return(DB_SUCCESS);
+}
+
+/*******************************************************************//**
+Releases only the named savepoint. Savepoints which were set after this
+savepoint are left as is.
+@return if no savepoint of the name found then DB_NO_SAVEPOINT,
+otherwise DB_SUCCESS */
+dberr_t
+trx_release_savepoint_for_mysql(
+/*============================*/
+	trx_t*		trx,			/*!< in: transaction handle */
+	const char*	savepoint_name)		/*!< in: savepoint name */
+{
+	trx_named_savept_t*	savep;
+
+	ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE, true)
+	      || trx_state_eq(trx, TRX_STATE_PREPARED, true));
+	ut_ad(trx->mysql_thd);
+
+	savep = trx_savepoint_find(trx, savepoint_name);
+
+	if (savep != NULL) {
+		trx_roll_savepoint_free(trx, savep);
+	}
+
+	return(savep != NULL ? DB_SUCCESS : DB_NO_SAVEPOINT);
+}
+
+/*******************************************************************//**
+Returns a transaction savepoint taken at this point in time.
+@return savepoint */
+trx_savept_t
+trx_savept_take(
+/*============*/
+	trx_t*	trx)	/*!< in: transaction */
+{
+	trx_savept_t	savept;
+
+	savept.least_undo_no = trx->undo_no;
+
+	return(savept);
+}
+
+/*******************************************************************//**
+Roll back an active transaction. */
+static
+void
+trx_rollback_active(
+/*================*/
+	trx_t*	trx)	/*!< in/out: transaction */
+{
+	mem_heap_t*	heap;
+	que_fork_t*	fork;
+	que_thr_t*	thr;
+	roll_node_t*	roll_node;
+	const trx_id_t	trx_id = trx->id;
+
+	ut_ad(trx_id);
+
+	heap = mem_heap_create(512);
+
+	fork = que_fork_create(NULL, NULL, QUE_FORK_RECOVERY, heap);
+	fork->trx = trx;
+
+	thr = que_thr_create(fork, heap, NULL);
+
+	roll_node = roll_node_create(heap);
+
+	thr->child = roll_node;
+	roll_node->common.parent = thr;
+
+	trx->graph = fork;
+
+	ut_a(thr == que_fork_start_command(fork));
+
+	trx_roll_crash_recv_trx	= trx;
+
+	const bool dictionary_locked = trx_get_dict_operation(trx)
+		!= TRX_DICT_OP_NONE;
+
+	if (dictionary_locked) {
+		row_mysql_lock_data_dictionary(trx);
+	}
+
+	que_run_threads(thr);
+	ut_a(roll_node->undo_thr != NULL);
+
+	que_run_threads(roll_node->undo_thr);
+
+	que_graph_free(
+		static_cast<que_t*>(roll_node->undo_thr->common.parent));
+
+	if (UNIV_UNLIKELY(!trx->rollback_finish())) {
+		ut_ad(!dictionary_locked);
+		goto func_exit;
+	}
+
+	ut_a(trx->lock.que_state == TRX_QUE_RUNNING);
+
+	if (!dictionary_locked || !trx->table_id) {
+	} else if (dict_table_t* table = dict_table_open_on_id(
+			   trx->table_id, TRUE, DICT_TABLE_OP_NORMAL)) {
+		ib::info() << "Dropping table " << table->name
+			   << ", with id " << trx->table_id
+			   << " in recovery";
+
+		dict_table_close_and_drop(trx, table);
+
+		trx_commit_for_mysql(trx);
+	}
+
+	ib::info() << "Rolled back recovered transaction " << trx_id;
+
+func_exit:
+	if (dictionary_locked) {
+		row_mysql_unlock_data_dictionary(trx);
+	}
+
+	mem_heap_free(heap);
+
+	trx_roll_crash_recv_trx	= NULL;
+}
+
+
+struct trx_roll_count_callback_arg
+{
+  uint32_t n_trx;
+  uint64_t n_rows;
+  trx_roll_count_callback_arg(): n_trx(0), n_rows(0) {}
+};
+
+
+static my_bool trx_roll_count_callback(rw_trx_hash_element_t *element,
+                                       trx_roll_count_callback_arg *arg)
+{
+  mutex_enter(&element->mutex);
+  if (trx_t *trx= element->trx)
+  {
+    if (trx->is_recovered && trx_state_eq(trx, TRX_STATE_ACTIVE))
+    {
+      arg->n_trx++;
+      arg->n_rows+= trx->undo_no;
+    }
+  }
+  mutex_exit(&element->mutex);
+  return 0;
+}
+
+/** Report progress when rolling back a row of a recovered transaction. */
+void trx_roll_report_progress()
+{
+	time_t now = time(NULL);
+	mutex_enter(&recv_sys.mutex);
+	bool report = recv_sys.report(now);
+	mutex_exit(&recv_sys.mutex);
+
+	if (report) {
+		trx_roll_count_callback_arg arg;
+
+		/* Get number of recovered active transactions and number of
+		rows they modified. Numbers must be accurate, because only this
+		thread is allowed to touch recovered transactions. */
+		trx_sys.rw_trx_hash.iterate_no_dups(
+			trx_roll_count_callback, &arg);
+
+		if (arg.n_rows > 0) {
+			service_manager_extend_timeout(
+				INNODB_EXTEND_TIMEOUT_INTERVAL,
+				"To roll back: " UINT32PF " transactions, "
+				UINT64PF " rows", arg.n_trx, arg.n_rows);
+		}
+
+		ib::info() << "To roll back: " << arg.n_trx
+			   << " transactions, " << arg.n_rows << " rows";
+
+	}
+}
+
+
+static my_bool trx_rollback_recovered_callback(rw_trx_hash_element_t *element,
+                                               std::vector<trx_t*> *trx_list)
+{
+  mutex_enter(&element->mutex);
+  if (trx_t *trx= element->trx)
+  {
+    mutex_enter(&trx->mutex);
+    if (trx_state_eq(trx, TRX_STATE_ACTIVE) && trx->is_recovered)
+      trx_list->push_back(trx);
+    mutex_exit(&trx->mutex);
+  }
+  mutex_exit(&element->mutex);
+  return 0;
+}
+
+
+/**
+  Rollback any incomplete transactions which were encountered in crash recovery.
+
+  If the transaction already was committed, then we clean up a possible insert
+  undo log. If the transaction was not yet committed, then we roll it back.
+
+  Note: For XA recovered transactions, we rely on MySQL to
+  do rollback. They will be in TRX_STATE_PREPARED state. If the server
+  is shutdown and they are still lingering in trx_sys_t::trx_list
+  then the shutdown will hang.
+
+  @param[in]  all  true=roll back all recovered active transactions;
+                   false=roll back any incomplete dictionary transaction
+*/
+
+void trx_rollback_recovered(bool all)
+{
+  std::vector<trx_t*> trx_list;
+
+  ut_a(srv_force_recovery < SRV_FORCE_NO_TRX_UNDO);
+
+  /*
+    Collect list of recovered ACTIVE transaction ids first. Once collected, no
+    other thread is allowed to modify or remove these transactions from
+    rw_trx_hash.
+  */
+  trx_sys.rw_trx_hash.iterate_no_dups(trx_rollback_recovered_callback,
+                                      &trx_list);
+
+  while (!trx_list.empty())
+  {
+    trx_t *trx= trx_list.back();
+    trx_list.pop_back();
+
+    ut_ad(trx);
+    ut_d(trx_mutex_enter(trx));
+    ut_ad(trx->is_recovered);
+    ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE));
+    ut_d(trx_mutex_exit(trx));
+
+    if (srv_shutdown_state != SRV_SHUTDOWN_NONE && !srv_undo_sources &&
+        srv_fast_shutdown)
+      goto discard;
+
+    if (all || trx_get_dict_operation(trx) != TRX_DICT_OP_NONE
+        || trx->has_stats_table_lock())
+    {
+      trx_rollback_active(trx);
+      if (trx->error_state != DB_SUCCESS)
+      {
+        ut_ad(trx->error_state == DB_INTERRUPTED);
+        trx->error_state= DB_SUCCESS;
+        ut_ad(!srv_undo_sources);
+        ut_ad(srv_fast_shutdown);
+discard:
+        /* Note: before kill_server() invoked innobase_end() via
+        unireg_end(), it invoked close_connections(), which should initiate
+        the rollback of any user transactions via THD::cleanup() in the
+        connection threads, and wait for all THD::cleanup() to complete.
+        So, no active user transactions should exist at this point.
+
+        srv_undo_sources=false was cleared early in innobase_end().
+
+        Generally, the server guarantees that all connections using
+        InnoDB must be disconnected by the time we are reaching this code,
+        be it during shutdown or UNINSTALL PLUGIN.
+
+        Because there is no possible race condition with any
+        concurrent user transaction, we do not have to invoke
+        trx->commit_state() or wait for !trx->is_referenced()
+        before trx_sys.deregister_rw(trx). */
+        trx_sys.deregister_rw(trx);
+        trx_free_at_shutdown(trx);
+      }
+      else
+        trx->free();
+    }
+  }
+}
+
+/*******************************************************************//**
+Rollback or clean up any incomplete transactions which were
+encountered in crash recovery.  If the transaction already was
+committed, then we clean up a possible insert undo log. If the
+transaction was not yet committed, then we roll it back.
+Note: this is done in a background thread.
+@return a dummy parameter */
+extern "C"
+os_thread_ret_t
+DECLARE_THREAD(trx_rollback_all_recovered)(void*)
+{
+	my_thread_init();
+	ut_ad(!srv_read_only_mode);
+
+#ifdef UNIV_PFS_THREAD
+	pfs_register_thread(trx_rollback_clean_thread_key);
+#endif /* UNIV_PFS_THREAD */
+
+	if (trx_sys.rw_trx_hash.size()) {
+		ib::info() << "Starting in background the rollback of"
+			" recovered transactions";
+		trx_rollback_recovered(true);
+		ib::info() << "Rollback of non-prepared transactions"
+			" completed";
+	}
+
+	trx_rollback_is_active = false;
+
+	my_thread_end();
+	/* We count the number of threads in os_thread_exit(). A created
+	thread should always use that to exit and not use return() to exit. */
+
+	os_thread_exit();
+
+	OS_THREAD_DUMMY_RETURN;
+}
+
+/****************************************************************//**
+Builds an undo 'query' graph for a transaction. The actual rollback is
+performed by executing this query graph like a query subprocedure call.
+The reply about the completion of the rollback will be sent by this
+graph.
+@return own: the query graph */
+static
+que_t*
+trx_roll_graph_build(
+/*=================*/
+	trx_t*	trx)	/*!< in/out: transaction */
+{
+	mem_heap_t*	heap;
+	que_fork_t*	fork;
+	que_thr_t*	thr;
+
+	ut_ad(trx_mutex_own(trx));
+
+	heap = mem_heap_create(512);
+	fork = que_fork_create(NULL, NULL, QUE_FORK_ROLLBACK, heap);
+	fork->trx = trx;
+
+	thr = que_thr_create(fork, heap, NULL);
+
+	thr->child = row_undo_node_create(trx, thr, heap);
+
+	return(fork);
+}
+
+/*********************************************************************//**
+Starts a rollback operation, creates the UNDO graph that will do the
+actual undo operation.
+@return query graph thread that will perform the UNDO operations. */
+static
+que_thr_t*
+trx_rollback_start(
+/*===============*/
+	trx_t*		trx,		/*!< in: transaction */
+	undo_no_t	roll_limit)	/*!< in: rollback to undo no (for
+					partial undo), 0 if we are rolling back
+					the entire transaction */
+{
+	ut_ad(trx_mutex_own(trx));
+
+	/* Initialize the rollback field in the transaction */
+
+	ut_ad(!trx->roll_limit);
+	ut_ad(!trx->in_rollback);
+
+	trx->roll_limit = roll_limit;
+	trx->in_rollback = true;
+
+	ut_a(trx->roll_limit <= trx->undo_no);
+
+	trx->pages_undone = 0;
+
+	/* Build a 'query' graph which will perform the undo operations */
+
+	que_t*	roll_graph = trx_roll_graph_build(trx);
+
+	trx->graph = roll_graph;
+
+	trx->lock.que_state = TRX_QUE_ROLLING_BACK;
+
+	return(que_fork_start_command(roll_graph));
+}
+
+/*********************************************************************//**
+Creates a rollback command node struct.
+@return own: rollback node struct */
+roll_node_t*
+roll_node_create(
+/*=============*/
+	mem_heap_t*	heap)	/*!< in: mem heap where created */
+{
+	roll_node_t*	node;
+
+	node = static_cast<roll_node_t*>(mem_heap_zalloc(heap, sizeof(*node)));
+
+	node->state = ROLL_NODE_SEND;
+
+	node->common.type = QUE_NODE_ROLLBACK;
+
+	return(node);
+}
+
+/***********************************************************//**
+Performs an execution step for a rollback command node in a query graph.
+@return query thread to run next, or NULL */
+que_thr_t*
+trx_rollback_step(
+/*==============*/
+	que_thr_t*	thr)	/*!< in: query thread */
+{
+	roll_node_t*	node;
+
+	node = static_cast<roll_node_t*>(thr->run_node);
+
+	ut_ad(que_node_get_type(node) == QUE_NODE_ROLLBACK);
+
+	if (thr->prev_node == que_node_get_parent(node)) {
+		node->state = ROLL_NODE_SEND;
+	}
+
+	if (node->state == ROLL_NODE_SEND) {
+		trx_t*		trx;
+		ib_id_t		roll_limit;
+
+		trx = thr_get_trx(thr);
+
+		trx_mutex_enter(trx);
+
+		node->state = ROLL_NODE_WAIT;
+
+		ut_a(node->undo_thr == NULL);
+
+		roll_limit = node->savept ? node->savept->least_undo_no : 0;
+
+		trx_commit_or_rollback_prepare(trx);
+
+		node->undo_thr = trx_rollback_start(trx, roll_limit);
+
+		trx_mutex_exit(trx);
+
+	} else {
+		ut_ad(node->state == ROLL_NODE_WAIT);
+
+		thr->run_node = que_node_get_parent(node);
+	}
+
+	return(thr);
+}